In recent years, soft silicone hydrogel contact lenses have become more and more popular because of their high oxygen permeability and comfort. By having a high oxygen permeability, a silicone hydrogel contact lens allows sufficient oxygen to permeate through the lens to the cornea with minimal adverse effects on corneal health. In addition to high oxygen permeability, on-eye movement of the lens is also required to ensure good tear exchange, and ultimately, to ensure good corneal health. Ion permeability is one of the predictors of on-eye movement, because the permeability of ions is believed to be directly proportional to the permeability of water. The methods described herein produce ophthalmic lenses having improved ion permeability without adversely affecting other properties of the lens.